1. Field of the Invention
The present invention concerns a new ceramide composition and a method for improving the firmness of skin.
2. The Related Art
Aging of skin is accompanied by a number of visible changes. The freshness of youth may change through the appearance of age spots;, sallowness, mottled pigmentation, dryness and alteration in firmness or elasticity. These phenomena appear to a different extent in any particular person. These changes can and probably do arise from different biological aging mechanisms. For this reason, no single chemical antidote is likely to simultaneously address all of the aging changes. The present invention concerns itself with the problem improving the firmness aspect of skin.
Cosmetic science within the last decade has seen the commercial advent of three broad categories of active skin agents. These are the cerarmides, alpha-hydroxycarboxylic acids (known as AHAS) and the retinoids. U.S. Pat. No. 4,950,688 (Bowser et al.) is one of the earliest references describing the synthesis and chemistry of ceramide 1 and its derivatives. WO 96/163635 (Lambers et al.) reports ceramide-containing compositions having a nigh capacity for recovering diminished water-retaining properties of pretreated or damaged skin. WO 95/29151 (Lambers et al.) describes synthesis procedures to obtain 2-alpha-hydroxycarboxylic acid based ceramide derivatives. EP 0 720 847 (Leveque et al.) describes use of ceramide 6 as a principle agent for reducing the loss of water from the skin and/or from keratin fibers. Cosmoferm, a division of Gist-brocades NV in a brochure (entitled "Human Skin-identical Ceramides", presented at an annual meeting of the British Society of Cosmetic Chemists, November 1994) provides an overview of ceramide chemistry. Related technology is disclosed in U.S. Pat. No. 476,661 (Pillai et al.) and U.S. Pat. No. 5,451,691 (Crawford et al.).
Ceramides have been delivered to the consumer in a variety of packages. The Elizabeth Arden Company was a pioneer in this area with a product known as "Ceramide Time Complex Capsules". Therein ceramide 1 and/or ceramide 3 were delivered in a cosmetic composition dispensed from a saturn-shaped gelatin capsule. See U.S. Pat. No. 5,063,057 (Spellman et al.).
Combinations of ceramide, alpha-hydroxycarboxylic acids and retinoids have been reported in EP 0 676 194 A2 (L'Oreal).
Despite the evident high level of activity, none of the aforementioned technology has addressed the issue of firming skin.
Accordingly, it is an object of the present invention to provide a cosmetic composition and method with the ability to achieve a perceptible improvement in the firmness of skin.
Another object of the present invention is to provide a cosmetic formula that not only improves firmness of skin but also lacks the irritation characteristics of previous systems incorporating ceramides, alpha-hydroxycarboxylic acids and/or retinoids.
These and other objects of the present invention will become more readily apparent from consideration of the following summary and detailed discussion.